Cook the sausage in a 10-inch skillet over medium-high heat until well browned. Pour off any fat.
Add the pepper and onion to the skillet and cook until the vegetables are tender-crisp, stirring occasionally. Stir in the soup, mustard and milk and heat to a boil. Reduce the heat to low. Cook for 10 minutes or until the sausage is cooked through, stirring occasionally.
Place 1 sausage link into each roll. Divide the pepper mixture among the rolls.